The most serious effect of long term delorazepam use is dependence, with withdrawal symptoms which mimic delerium tremens presenting when delorazepam use is discontinued.
Subjects who are physically dependent on benzodiazepines may suffer benzodiazepine withdrawal symptoms, including seizure, upon rapid administration of flumazenil.
Use in the last trimester may cause fetal drug dependence and withdrawal symptoms in the post-natal period as well as neonatal flaccidity and respiratory problems.